Brush-lifting device



March 19, 1929. G, H. LELAND BRUSH LIFTING DEVICE Filed Aug. 26, 1927 2Sheets-Sheet //v v/v T0 R. 650965 H. L EL 4N0.

4 TT0/PNE Y March 19, 1929. G H L LAND 1,706,068

BRUSH LIF'fING DEVICE 7 Filed Aug. 26, 1927 2 Sheets-Sheet 2 //V Vf' NTOR 60R6 H. LEI. AND.

ATTOHNIE'Y Patented Mar. l9, 1929.

UNITED STATES A "1,706,068 PATENT OFFICE.

'enonen n. mun, .or nan-on, omo, assrenon or our-mum 'ro 'rnn Luannanaem c comm, or narrow, onto, a coarom'rron or 0310.

Barren-turtles nnvroa.

Application filed August 38, 1927. Serial No. 215,818.

This invention relates to a brush lifting device for use with electricmotors and the ike. In certain types of electric motor it is desirablethat the brush should be lifted out 6 of engagement with the commutator.For example, a repulsion induction motor starts as a repulsion motor andafter it has attained also results in a noise which is objectionable.

One object of the invention is to provide a simple eflicient mechanismfor automatically lifting the brushes out of contact with the commutatorwhen the motor has attained a predetermined speed.

A further object of the invention is to provide such a mechanism inwhich the brushes will be permitted to have movement with relation tothe lifting mechanism, asthey wear away, but willbe engaged by thelifting mechanism and moved out of contact with the commutatorregardless of the positions which they have assumed with relation to thelifting mechanism.

Other objects of the invention will appear as the mechanism is describedin detail.

In the accompanyin drawings Fig. I is a rear elevation of a rush liftingmechanism embodying my invention, and a portion of the commutator; Fi 2is a bottom plan view of the brush lifting mechanism; Fig

3 is a transversesectional view taken on the line 3-3 of Fig.1; 'Fig. 4is a section taken on the-line 44 of Fig. 1; Fig. 5 is a rear elevation,partly broken away of a modified 40 form of the brush lifting mechanism;and

Fig. 6 is a rear elevation of another modified form of the invention. I

In these drawings I have illustrated several embodimentsof the inventionall of which embed the same essential features of construction ut whichdiffer in certain details of the mechanism. It will beunderstood thatthese several forms of the apparatus have been chosen for the purposesof illus tration only and that the mechanism may take various forms andthe several parts thereof may be arranged in 'various ways. In that formof the apparatus illustrated in Figs.'1 to 4- the brush liftingmechanism is shown in connection with a commutator cuiting device aredivided into groups by 1 of a motor, which is of ordinary constructionand is mounted on the motor shaft 2 and provided with the usualinsulated commutator bars 3. Cooperating with the commutator is a shortcircuitin device consisting of a series of centrifugally operatedcontact weights 4 arran ed circumferentially of the motor shaft anconfined between the face of the commutator and a retainin late 5.Extending about the outer edges 0% t e contact weights 4 is an annularcontractile band or spring 6 which resists the outward movement of theweights by centrifu al force and returns the same to their norma orretracted positions when the centrifugal force decreases. Also mountedabout the commutator shaft is a centrifugal device consisting of aseries of weights 7 each having at its outer end a forwardly extendingflange 8 the several flanges being so arranged that they will form apractically continuous annular flange on the centrifugaldevice as awhole. The several weights of the short cirmeans of separator plates 9which have at their inner ends circumferentially arranged portions 10upon which the weights of the respective groups are supported. Theseseparator plates .9 have forwardly extending projections or lugs 11which extend through slots in the respective weights 7 of thecentrifugal device so that they are connected with and held againstradial movement with relation to said centrifugal device and the spring6 of the short circuiting device also serves to resist the outwardmovement of the weights of the centrifugal device. The short circuitingdevice and the centrifugal device do not in themselves form any part ofthe present invention and it is not necessary to describe the same indetail. It will be understood that when the motor is idle or running atlow speed the spring 6 will hold'both devices in their retractedpositions and when the motor attains a certain predetermined speed cen-100 trifugal force will move both devices outwardly against the actionof the spring 6,

' 05 The brush lifting mechanism of Fi .lto

'4 comprises a supporting member or p ate 12;:

which is rigidly mounted on a fixed support; such as the motor casing,which is not here f /"f shown. Pivotally mounted on the supportingstructure aretwo brush supporting members which are preferably in theform of arms 13 pivotally mounted upon the supporting structure andextending in opposite-directions circumferentially to the commutator. Inthe present instance, the two brush supporting arms are mounted on'separate studs 14 and each arm comprises parallel side members connectedone to the other at their outer ends by a: transverse portion 15, thusforming at the outer end of the arm a guideway for the brush 16. Ifdesired, each arm may be formed from a single piece of metal bent to thedesired shape. lifting arms are actuating devices, which preferablyconsist of arms 17 pivotally mounted on the respective studs 14 and, ashere shown, each actuating arm comprises parallel side members mountedat their inner ends on the studs 14 and connected at their outer ends bya transverse portion 18 which constitutes a clamping member to engagethe brush and retain the same in a fixed position in the guideway. Thisclamping member or plate 18 is so arranged with relation to the guidewayfor the brush that when the actuating device is in its normal positionthe brush will be free to move with relation to the supporting arm 13and the actuating device but when the actuating device is moved aboutits axis it will engage thebrush and clamp the same against the outerwall 15 of the guideway, thus not only holding the brush againstmovement with relation to the brush lifting arm but also connecting theactuating device with the brush lifting arm so that further movement ofthe actuating device will lift the arm and the brush. Any suitable meansmay be provided for pressing the brush against the commutator and formoving the brush supporting. arms toward the commutator, but this meanspreferably consists of a pressure device of such a character that thepressures on the two arms and on the two brushes will be respectivelyequalized and a predetermined ratio will be malntained between thepressure on each arm and the pressure on the brush carried by thatarm.As here shown, I have provided the two brush lifting arms with pressuremembers or bars 19 which are pivotally mounted at 20 on the respectivearms near the inner ends thereof and which have their outer ends curved,as

shown at 21, and resting upon the upper ends of the respective brushes16. A spring 22 is connected at its ends with the two pressure members19. In the present instance, the ends of the spring are connected withlugs 23 struck from the respective pressure members and, bent inwardly.The points of connection between the spring and the pressure members areso arranged that the spring will tend to press the brushes intoengagement with the commutator and to move the brush supporting armsabout their axes, the arrangement Cooperating with the brush being suchthat the pressure is properly divided between the brushes and the arms,the pressure on the two arms being substantially equal and the pressureon the two brushes being substantially equal, and, further, the pressureon each arm having a predetermined ratio to the pressure on the brushcarried by that arm. The pressure members 19 are provided with resilientfingers 24, preferably struck from the members and bent downwardly, toreceive clips 25 by means of which conductors 26 are electricallyconnected with the pressure members, these conductors being connected attheir other ends with the re spective brushes.

The actuating devices 17 may be operated in any suitable manner. In thedevice here shown, the two actuating arms 17 have inwardly extendingportions 27 which are provided with opposed contact surfaces, thesecontact surfaces being,'in the present instance, in the form of rollers28 mounted between the projections 27 on the two parts of the respectivearms. A centrifugall actuated stud 29 is arranged normally be ow thecontact surfaces of rollers 28 of the actuating devices and ispreferably carried by a lever 30 which is pivotally mounted at 31 on asupportingstructure 12 and has its inner end turned downwardly andprovided with a transverse channel 32 into which the flange 8 of thecentrifugal device 7 projects. Conscquentlythe outward movement of thecentrifugal device will impart outward movement to the stud 29, thusforcing the same between the opposed contact portions of the twoactuating devices and imparting pivotal movement to those devices. Thefirstportion of this movement causes the clamping plates 18 to grip thebrushes and to establish connection between the actuating devices andthe brush supporting arms, and the further movement of the actuatingdevices lifts the arms and moves the brush out of contact with thecommutator. When the stud 29 has been moved to its outermost positionits horizontal diameter will lie beyond the plane passing through theaxes of the two rollers and these rollers will support the stud in itsoutermost position and the stud while in this position will prevent therollers from returning to their normal positions, thus retaining thebrushes out of contact with the commutator. I

to permit of this, I have provided a stop'to 112 extending rearwardlyfrom the supporting plate 12 and arranged between the brush supportingarms so that*the inner edges of.

these arms will engage the lug before the outer ends of the arms canengage the commutator.

In Fig. 5 I have illustrated a modified form which differs from the formabove described principally in the manner of applying the springsthereto. As shown in this figure the mechanism comprises asupporting"structure or plate 33 and the brush lifting membersare in theform of arms, 34 and 34, pivotally mounted on a single stud 35, carriedby the supporting plz te, and extending in opposite directionscircumferentially of the commutator 1. The arms are similar inconstruction to those above described and each is provided at its outerend with a guideway for the brush 36. The actuating devices 37 are inthe form of arms pivotally mounted on the single stud 35 and havingopposed contact surfaces or rollers 38 arranged to be engaged by acentrifugally operated stud 39, each arm having at its outer end aclamping member 40 to hold the brush against movement and to connect theactuating device with the lifting arm.

Each of the brush lifting arms has connected therewith andpreferablyformed integral therewith, a supplemental arm,.41 and 41",which extends on that side of the stud 35 opposite the brush liftingarm, the supplemental arm 41 of the brush lifting arm 34 extendingalongside of the brush lifting arm 34 and the supplemental arm 41 of thebrush lifting arm 34 extends alongside, of the brush lifting arm 34.Mounted lupon the outer end of each of the supplemental arms.

is a spring 42 having that portion which is connected with the arm inthe form of a coil and having its outer portion substantially flat andbearing upon the end of the adjacent brush. This arrangement is suchthat each of the springs 42- will tend to press the brush *of onesupporting arm against the commutae tor and to move the other supportingarm about its axis. When the two brush supporting arms are moved abouttheir axes by the actuating devices each supporting arm will be movedtowardthe supplemental arm of the other supporting arm, thus increasingthe tension on the springs42. I

In Fig. 6 I have shown a further slight modification of the mechanism.As there shown, the brush supporting arms 43 are pivotally mounted onseparate studs 44 carried by a supporting structure or plate 45; In

this instance each arms consists of a single.

member, the outer end of which is bent laterally, as shown at 46, andthen rearwardly,

as shown at 47, to form a guide for the brush 48. The transverse portion46 of the guide projects some distance above the upper ed e of the armand beyond the end'of the brus The actuating devices comprise arms 49pivotally mounted on the respective studs 44 and each having its outerend bent laterally, as shown at 50, to provide a clamping plate whichcooperates with a wall of the guideway to secure the brush againstmovement and to connect the actuating device with the arm. Eachactuating arm has an inwardly extending portion 51 and these portionsare provided with opposed contact surfaces but these contact surfacesare in the form of fixed beveled surfaces 52 instead of rollers andareacted upon by an operating member or stud 53 in the manner describedin connection with the mechanism of Fig. 1. Connected with each stud 44are two. flat springs, 54 and 55, these springs having those ends whichare connected with the studs coiled about the studs and having theirother ends bearing respectively upon the transverse outer portion of thearm and upon the end of the brush, the transverse portion of the armbeing slotted, as shown at 56, topermit the inward movement of thespring 55. A stud or projection 57 extending rearwardly from thesupporting structure 33 lies between the edges of the two brushsupporting arms to limit their inward movement.

While I have shown and described certain embodiments of my invention Iwish it to be understood that I do not desire to be'limited to thedetails thereof as various modifications may occur to a person skilledin the art.

Having now fully described my invention, what I claim as new and desireto secure by Letters Patent, is: 1

1. In a brush lifting mechanism for an electric motor or the like, asupporting structure, a brush supporting member pivotally mounted onsaid structure, extending circumferentially of the commutator of saidmotor, and having at its outer end a guideway for a brush, abrush insaid guideway, an actuating device associated with said brushsupportingmember and havinga part movable with relation thereto to clampthe brush in a contact portion, and an operating member" to engage saidcontact portion and cause said actuating device to first clamp the brushin said guideway and to.tl1en impart movement to said brush supportingmember to lift the brush.-

2. In a brush lifting mechanism for'an electric motor or the like, asupporting structure, a brush supporting arm pivotally mounted onsaidstructure, extending circumguideway, an actuating arm associatedwith said brush supporting arm, mounted 'for movement about the axis ofsaid arm and having a part forming a clamping member to engage the brushin said guideway, yieldable means for moving said arm and said brushtoward said commutator, and an operating member arranged to engage saidactuating arm and first move said arm with relation to said brushsupporting arm and then cause said actuating arm to impart movement tosaid brush supporting arm.

3. In a brush lifting mechanism for an electric motor or the like, asupporting structure, a brush supporting arm arranged circumferentiallyof the commutator of said motor and comprising parallel members spaced:1 art and pivotally mounted at their inner ends on said "supportingstructure and connected at their outer ends by a transverse portion toform a guideway for a brush, a

- brush in said guideway, an actuating arm piv- Gil otally mounted onsaid supporting structure, arranged between the two members of saidbrush supporting arm and having at its outer end a part spaced from thetransverse portion I of said brush supporting arm andadapted to clampthe brush in said guideway, and an operating member to engage saidactuatin arm and move the same with relation to said brush supportingarm to cause the brush to be clamped in said guideway and to then impartmovement-to said brush supporting arm.

4. In a brush lifting mechanism for an electric motor or the like, asupporting structure, brush supporting members pivotally mounted on saidstructure and each-having a guideway for a brush, a brush in saidguideway, actuating devices associated with the respective brushsupporting members and each having a part movable with relation to theadjacent brush supporting member to clamp the brush in the guideway ofsaid member, said actuating devices having opposed contact parts, and anoperating member to engage said opposed contact parts and cause saidactuating devices to first clamp the brushes in the respective guidewaysand to then impartmovement to said brush sup porting members to liftsaidbrushes.

5. 'In a 'brush lifting mechanism for an electric motor or thelike, asupporting structure, brush supporting arms pivotally mounted on saidstructure and each having a art shaped to form a guideway for a brush, abrush in said guideway, actuating arms associated with the respectivebrush lifting arms and mountedfor movement about the axes of therespective arms, each actuating arm having a part forming a clampingmember to engage the brush in said guideway, yieldable means for movingsaid arms and said brushes toward said commutator, said actuating armshaving opposed contact parts, and an operating member arranged to engagethe opposed contact parts of said actuating arms and first move saidarms with relation to the support-v ing arms and then cause saidactuating arms to impart movement to the brush supporting arms.

6. In a brush lifting mechanism for an electric motor or the like, asupporting. structure, brush supporting arms pivotally mounted on saidstructure and each having a art shaped to form a guideway for a brus a.brush in said guideway, actuating arms associated with the respectivebrush lifting arms and mounted for movement about the axes of thesupporting arms, each actuating arm having a part forming a clampingmemberto engage the brush in said guideway, yieldable means for movingsaid arms and said brushes toward said commutator, said actuating armshaving inwardly extending projections provided with contact surfaces, anoperating stud to engage said contact surfaces and impart movement tosaid actuating arms, and 'cen trifugally operated means for actuatingsaid stud.

7 i In a brush lifting mechanism for an electric motor or the like, asupporting structure, brush supporting arms each comprising parallelmembers spaced apart and pivotally mounted at their inner ends on saidsupporting structure and connected at their outer ends by a transverseportion to form aguideway for a brush, a brush in said guideway,actuating arms pivotally mounted on said supporting structure, arrangedbetween the two members of the respective brush supporting arms and eachhaving at its outer end a transverse-portion spaced from the-transverseportion of said brush su porting arm and adapted to clamp the brusbetween the same an the transverse portion of said supporting arm, saidactuating arms having opposed contact surfaces, and an operating membertoengage said opposed contact surfaces and impart movement to saidactuating devices.

8. In a brush lifting mechanism for an electric motor or the like, abrush, a movable brush supporting member having means for supportingsaid brush thereon for movement relatively thereto during the operationof said motor, a device to act on said supporting member and said brushto press the same yieldably toward the commutator of said motor, saiddevice comprising means to main tain a predetermined ratio between thepressure on said brush supporting member and the pressure on said brush.

9. In a brush lifting mechanism for an electric motor or .the like, abrush, a movable brush supporting member having means for supportingsaid brush thereon for movement relatively thereto. during the operationof said motor, a pressure device having diiferent ing a predeterminedratio to the moaooa tained at a predetermined ratio to the pressure onsaid brush.

10. In a brush lifting mechanism for an electric motor or the like, abrush, a movable brush supporting member having means for supportingsaid brush thereon for movement re atively thereto, and a pressuredevice comprising a member having parts spaced one from the other andarranged to act respectively on said brush supporting member and a saidbrush, and a spring acting on said member at a 'point so arranged withrelation to said parts thereof that the pressure on said supportingmember will have a predetermined ratio to the pressure on said brush.

11. In a brush lifting mechanism for an electric motor or the like,movable brush supporting members each having means for supporting abrush thereon for movement with relation thereto during the operation ofsaid motor, brushes carried by said supporting members, and means forcausing said brushes to bear upon the commutator of said motor withequalized pressure and to cause said supporting members to bepressedtoward said commutator with equalized pressure havpressare onsaid brushes. I a

12. In a brush lifting mechanism for an electric motor or the like,movable brush sup? porting members each having means for sup porting abrush thereon for movement withrelation thereto during the operation ofsaid motor, brushes carried by said supporting members, and a pressuredevice having parts to act on said supporting members and on saidbrushes to press the same toward the commutator of said motor andcomprising means for equalizing the pressure ofsaid supporting membersand for equalizing the pressure on said brushes, and for maintaining thepressure on said supporting members at a predetermined ratio to thepressure on said brushes. v I

13. In a brush lifting mechanism for an electric motor or the like,movable brush supporting members each having means'for supporting abrush thereon for movement withrelation thereto during the operation ofsaid motor, brushes carried by said supporting members, pressure membersto when the respective supporting members and the brushes carriedthereby and ress the same toward the commutator of sai motor, and ayieidable device acting on said pressure members to cause the same toexert equal pressure on said supporting members and to exert equalpressure on said brushes thepressure on said brushes having apredetermined ratio to the pressure on said su porting members.

14. In a brush iftin mechanism for an electric motor or the li a, a pairof pivoted brush supporting arms each having mea,ns

being spaced a greater for supporting a brush thereon for movement withrelation thereto, brushes carried b said supporting arms, pressuremembers eac connected near one end with one of said arms and having itsother end arranged to act on the brush carried by thatarm, and anexpan-.

sion spring connected at its ends with the respective pressu gemembers,the points of connection of the sprin with said pressure members beingarranged to cause the pressure on said arms to bear a predetermined vratio to the pressure on said brushes.

- 15. In a brush lifting mechanism for an electric motor orthe like, apair of ivoted supporting arms each having means or supporting a brushthereon for movement with relation thereto, brushes carried by saidsupporting arms, pressure members each ivotally connected at one endwith one 0 said arms near the axis of said arm and having its other endarranged to'bear on the brush carried by that arm, and a coiled springconnected at its ends with the respective pressure members, the point ofconnection of said spring with each of said ressure members istance fromthe brush engaging part of said member than it is spaced from the axisof said member.

16. In a brush. lifting mechanism for an electric motor or the like, asupporting structure, brush supporting arms pivotally mounted at theirinner ends on said supporting structure and each having at its outer enda guideway for a brush, a brushin each guide- Way, actuating armsprvotally mounted on said supporting structure and having at their endsportions to clamp the brushes in the guideways of said supportinactuating arms having oppose contact surfaces, an operating member toengage said opposed contact surfaces and impart movement to saidactuating devices, a bar pivotally mounted on each brush supporting armnear the inner end of said arm and having its outer portion bearing uponthe brush supported by that arm, and a spring acting upon the bars ofthe twoarms to move said brush supportarms, said ing arms about theiraxis and to exert pres sure on said brushes.

17. In a brush lifting mechanism for an electric motor or the like, asupporting strucends by a transverse portion to form a ideway for abrush, a brush in each 1 eway, actuating arms pivotally mounteonsaidsupporting structure, arranged between the two members of therespective brush supporting arms and each having at its'outer end atransverse portion spaced from the transverse portion of said brushsupporting arm and adapted to clamp the brush between the same and thetransverse portion of said supporting arm, said actuating arms havingopposed contact surfaces, an operating memher to engage said opposedcontact surfaces and im art movement to said actuating devices, a arpivotally mounted on each brush supportin arm near the inner end of saidarm and aving its outer portion bearing u on the brush supported by thatarm, each 0 said bars havin near its pivoted end an in lparallel membersspaced apart and pivotally mounted at their inner ends on said supportstructure and connected at their outer ing1 on s by a transverse portionto form a guideway for a brush, a brush in each guideway, actuating armspivotally mounted on said supporting structure, arranged between the twomembers of the respective brush supporting arms and each having at itsouter end a transverse portion spaced from the transverse portion ofsaid brush supporting arm and adapted to clamp the brush between thesame and the transverse portion of said supporting arm, said actuatingarms having opposed contact surfaces, an operating member to engage saidopposed contact surfaces and impart movement to said actuating devices,a bar pivotally mounted on each brush supporting arm near the inner endof said arm and having its outer portion bearing upon the brushsupported by that arm, a spring acting upon the bars of the two arms tomove sald brush supporting arms about their axes and to exert ressure onsaid brush, and means for electrica ly connecting said brushes with therespective bars.

19. In a brush lifting mechanism for an electricmotor or the like, asupportingstructure, brush supporting arms each comprising parallelmembers spaced apart and pivotally mounted at their inner ends on saidsupportin structure and connected at their outer en s by a transverseportion to form a guideway for a brush, a brush in each guideway,actuating arms pivotally mounted on said supporting structure, arrangedbetween the two members of the respective brush supporting arms and eachhaving at its outer end a transverse portion spaced from the transverseportion of said brush supporting arm and adapted to clamp the brushbetween the same and the transverse portion of said supporting arm, saidactuating arms having opposed contact surfaces, an operating member toengage said opposed contact surfaces and impart movement to saidactuating devices, a bar pivotally mounted on each brush supporting armnear the inner end of said arm and having its outer portion bearing uponthe brush supported by that arm, a spring acting on the bars of the twoarms to move, sai brush supporting arms about their axes and to exertpressure on said brush, each of said bars having a resilient fingerspaced fromone surface thereof, conductors connected with the respectivebrushes, and clips secured to the respective conductors and having partsadapted to be confined between the resilient fingers and the bodyportions of the respective bars.

20. In a brush lifting mechanism for an electric motor or the like, asupporting structure, brush supporting arms pivotally mounted on saidstructure, extending in opposite directions about the commutator of saidmotor and each having a guideway for a brush, a brush in each guideway:actuating devices associated with the respective brush supporting armsand each having a part movable with relation to the adjacent brushsupporting member to clamp the brush in the guideway of said member, anoperating device to impart operative movement to said actuating devices,a spring acting on said brush supporting arms to move the same, towardsaid commutator, and a part carried by said supporting structure andarranged between the adjacent edges of said brush supporting arms tolimit the inward movement thereof.

21. In a brush lifting mechanism for an electric motor or the like, asupporting structure, brush supporting arms pivotally mounted inseparate axes on said supporting structure, and each having near itsouter end a guideway for a brush, a brush in each guideway, actuatingarms extending parallel with the respective brush supporting arms and"pivotally mounted for movement about the axes of said arms,\eachactuating arm having at its outer end a part to engage the brush andclamp the same in a guideway of the brush lifting arm and therebyconnect said actuating device with said arm, yieldable means tending tomove said brush supporting arms and said brushes toward said commutator,said actuatingarms having opposed contact parts, and an operating memberarranged to engage said contact parts and impart operative movement tosaid actuating devices.

In testimony whereof, I afiix my signature hereto GEORGE H. LELAND.

